Abstract
Complex thermally grown oxides (TGOs) are formed on a single-crystal Ni-based superalloy due to a large fraction of alloying elements. Combining atom-probe tomography and transmission electron microscopy analyses, the three-dimensional elemental distributions of metal oxides of the spinel and refractory metal-oxide regions are presented. A spinel-type oxide, Ni(Cr,Al)2O4, is formed with a crystallographic orientation relationship with the alloy substrate, which decomposes into other oxides. The sequence of oxides observed in the TGO are NiO → Cr 2O3 → Ta2O5 → NiTaO 4, NiTa2O6 → Ni(Cr,Al)2O 4 → Al2O3.
Original language | English (US) |
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Pages (from-to) | 909-912 |
Number of pages | 4 |
Journal | Scripta Materialia |
Volume | 68 |
Issue number | 11 |
DOIs | |
State | Published - Jun 2013 |
Funding
The atom-probe tomography measurements were performed at the Northwestern University Center for Atom-Probe Tomography (NUCAPT). The LEAP 4000X-Si tomograph was purchased and upgraded with funding from NSF-MRI (DMR-0420532) and ONR-DURIP (N00014-0400798, N00014-0610539, N00014-0910781) grants. We gratefully acknowledge the Initiative for Sustainability and Energy at Northwestern (ISEN) for grants to upgrade the capabilities of NUCAPT, and also for a booster award that initiated the research reported in this paper. We also kindly thank Dr Ben Nagaraj, GE Aviation, Cincinnati, Ohio, for specimens and discussions, and Dr Yaron Amouyal (now at Technion-Israel Institute of Technology) for his generous initial participation in this research.
Keywords
- Atom-probe tomography
- Metal oxides
- Ni-based superalloy
- Spinel
- Transmission electron microscopy
ASJC Scopus subject areas
- General Materials Science
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys